This invention relates in general to respiratory therapy devices and, in particular, to a respiratory therapy device for use by a single patient. More specifically, but without restriction to the particular use which is shown and described as the best mode contemplated for carrying out this invention, the invention relates to an inexpensive single user respiratory therapy device that provides substantially resistance free inhalation, and selectively controlled resistive exhalation, with a pressure range monitoring unit to provide the patient with visual feed-back to enable the patient to monitor the proper usage of the device.
Persons who suffer from pulmonary problems that result in large amounts of mucus being produced in the lungs often require assistance in the removal of these secretions. If these secretions are allowed to remain in the lungs, airway obstruction occurs resulting in poor oxygenation and possible pneumonia and/or death. One of the clinically recognized treatments for this condition is a technique known as positive expiratory pressure therapy or PEP. With PEP therapy, a patient exhales against a resistance to generate expiratory pressure at a substantially constant rate of flow. Prescribed expiratory pressures are generally in the range of 10-20 cm H2O, although other pressure ranges and pressures can be used.
PEP therapy has been documented by clinical research as equal to or superior to standard chest physiotherapy techniques which, while effective, are time consuming and not well tolerated by many patients who have difficulty breathing for extended periods of time in certain positions required for administration of standard chest physiotherapy. Accordingly, PEP therapy is believed to provide significant advantages to patients suffering from cystic fibrosis, and is felt to be an eventual replacement for chest physiotherapy for many patients.
In the use of PEP therapy, a patient breathes through an orifice restricter to generate a positive pressure in the lungs during exhalation, with the pressure falling to zero at the end of exhalation. By selection of a proper-sized orifice, a given pressure is determined for the exhalation flow rate generated by an individual patient. This extended, substantially constant flow, elevated-pressure exhalation has been shown to be effective for moving secretions trapped in the lungs to the larger airways where they can then be removed through coughing.
The PEP therapy devices presently in use are very effective in the administration of the PEP therapy. However, these devices require the use of an expensive pressure gauge, which is not a part of the PEP device, but separately connected to the device when in use. With such devices, unless the hospital or patient purchases an expensive pressure gauge to connect to the device, the patient is unable to monitor its use. Without the ability to monitor the expiratory pressure, the patient is unable to determine if the PEP therapy technique is being properly administered.
While an expensive pressure gauge can be connected to the device to display the expiratory pressure being exerted by the patient, proper administration of the PEP therapy does not require the determination by the patient of an exact gauge pressure. The PEP therapy can be properly administered as long as the patient can be made aware when the device is in use that the expiratory pressure is being maintained within a proper predetermined pressure range.